American Tower Corporation
MX ˙ BMV ˙ US03027X1000
SecurityMX:AMT / American Tower Corporation
InstitutionSummit Trail Advisors, Llc
Latest Disclosed Ownership16,128 shares
Latest Disclosed Value $ 2,783,379
Summit Trail Advisors, Llc reports 17.87% increase in ownership of AMT / American Tower Corporation

On May 12, 2026 - Summit Trail Advisors, Llc filed a 13F-HR form disclosing ownership of 16,128 shares of American Tower Corporation (MX:AMT) valued at $2,783,379 USD as of March 31, 2026. The entity filed a previous 13F-HR on February 17, 2026 disclosing 13,683 shares of American Tower Corporation. This represents a change in shares of 17.87% during the quarter.

Institutional Ownership: 13F and NPORT Filings

The Security and Class in the table below are shown exactly as filed by the investor. We do our best to track continuity of investments through acquisitions, and this will be reflected in the table as changes in names. In addition to descriptive data, performance of the investment is shown over time. To calculate quarterly performance, we first calculate cost basis of the shares purchased during the quarter, then use that to calculate gross profit. Quarterly return is Gross Profit / Starting Portfolio value.

Note that cost basis is calculated and stored in thousands, so small quarterly changes in shares frequently result in a cost basis of zero.

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Disclosed Equity Positions (from 13F/NPORT Filings)
File
Date		 Effective
Date		Form Security Class ID Avg Price
Paid (Est)		 Reported
Shares		 ΔShares ΔShares
(%)		 Reported
Value
(x1000)		 ΔValue
(%)		 Alloc
(%)		 ΔAlloc ΔAlloc (%) Cost Basis
(x1000)		 Unrealized
Gain/Loss
(x1000)
2026-05-12 2026-03-31 13F AMERICAN TOWER COM 03027X100 16,128 2,445 17.87 2,783 14.76 0.0399
2026-02-17 2025-12-31 13F AMERICAN TOWER CORP COM 03027X100 13,683 -1,673 -10.89 2,425 -18.49 0.0419
2025-11-14 2025-09-30 13F AMERICAN TOWER CORP COM 03027X100 15,356 3,206 26.39 2,975 9.90 0.0411
2025-08-14 2025-06-30 13F AMERICAN TOWER CORP COM 03027X100 12,150 3,100 34.25 2,707 37.48 0.0465
2025-04-28 2025-03-31 13F AMERICAN TOWER CORP COM 03027X100 9,050 2,638 41.14 1,969 66.02 0.0650
2025-01-29 2024-12-31 13F AMERICAN TOWER CORP COM 03027X100 6,412 87 1.38 1,186 -19.37 0.0438
2024-11-12 2024-09-30 13F AMERICAN TOWER CORP COM 03027X100 6,325 654 11.53 1,471 32.52 0.0365
2024-08-13 2024-06-30 13F American Tower REIT Com COM 03027X100 5,671 795 16.30 1,111 15.26 0.0292
2024-04-23 2024-03-31 13F AMERICAN TOWER CORP COM 03027X100 4,876 551 12.74 963 2.34 0.0256
2024-02-06 2023-12-31 13F AMERICAN TOWER CORP COM 03027X100 4,325 99 2.34 941 35.59 0.0311
2023-10-30 2023-09-30 13F AMERICAN TOWER CORP COM 03027X100 4,226 371 9.62 695 -7.96 0.0256
2023-07-25 2023-06-30 13F AMERICAN TOWER CORP COM 03027X100 3,855 1,564 68.27 755 61.11 0.0285
2023-05-04 2023-03-31 13F AMERICAN TOWER CORP COM 03027X100 2,291 345 17.73 468 13.04 0.0189
2023-02-07 2022-12-31 13F American Tower REIT Com COM 03027X100 1,946 -1,058 -35.22 415 -35.81 0.0184
2022-11-10 2022-09-30 13F American Tower REIT Com Stock 03027X100 3,004 -514 -14.61 645 -28.65 0.0349
2022-08-09 2022-06-30 13F American Tower REIT Com COM 03027X100 3,518 1,532 77.14 904 81.16 0.0559
2022-05-16 2022-03-31 13F American Tower REIT Com EQUITY 03027X100 1,986 -106 -5.07 499 -18.86 0.0404
2022-02-11 2021-12-31 13F American Tower REIT Com Equity 03027X100 2,092 2,092 615 0.0397
2021-02-16 2020-12-31 13F iShares TR S&P 500 Growth ETF Equity 03027X100 0 -1,118 -100.00 0 -100.00
2020-11-16 2020-09-30 13F/A-1 American Tower REIT Com Equity 03027X100 1,118 1,118 266 0.0514
2020-11-16 2020-09-30 13F iShares TR S&P 500 Growth ETF Equity 03027X100 42,516 2,564
2019-02-13 2018-12-31 13F AMERICAN TOWER CORP NEW COM EQUITY 03027X100 0 -1,053 -100.00 0 -100.00
2018-11-14 2018-09-30 13F AMERICAN TOWER CORP NEW COM EQUITY 03027X100 1,053 1,053 154 0.0340
2018-08-10 2018-06-30 13F AMERICAN TOWER CORP NEW COM EQUITY 03027X100 0 -1,882 -100.00 0 -100.00
2018-05-22 2018-03-31 13F/A-1 AMERICAN TOWER CORP NEW COM EQUITY 03027X100 1,882 85 4.73 236 -7.45 0.0401
2018-05-21 2018-03-31 13F AMERICAN TOWER CORP NEW COM EQUITY 03027X100 236,091 234,294 236
2018-02-14 2017-12-31 13F AMERICAN TOWER Units 03027X100 1,797 1,797 255 0.0322
Legend
Shares
The total number of shares held by the institution at the end of the reporting period (the effective date). This is provided in the filing.
Value
The total value of the shares as of the effective date. This is provided in the filing.
Avg. Share Price
The weighted average share price of the shares held by the institution. We use FIFO accounting to determine this price
Class
This is the security class as indicated by the filer. There are a variety of values for this field. Common values include "EC" = equity common, "EP" - equity preferred
Allocation (%)
The percent of the institution's portfolio that this position represents. This is provided in NPORT filings. For 13F filings, we calculate it.
Change in Allocation
The change in allocation from the prior reporting period. This is calculated as current allocation - prior allocation.
Change in Allocation (%)
The percent change in allocation from the prior reporting period. This is calculated as (current allocation - prior allocation) / prior allocation.
Cost Basis
The total cost of the shares held. This is calculated as reported shares * avg. share price
Unrealized Gain/Loss
This is the market value of the position as of the effective date minus the cost basis.